1. Field of the Invention
The present invention is directed to a method and device for the removal of thin surface films of petroleum products from a water's surface.
2. Description of the Related Art
Various devices have been used for the removal of petroleum films. Such devices have utilized floats, skimmers and other above water devices which are made in the form of a spiral, labyrinth or plates. Such devices are shown in Soviet patent document nos. 1059059 (class "YE" 02V15/04) and 1017775 (class "YE" 02V17/00).
Those known devices, however, have many failings and shortcomings. Labyrinths slow the removal of the petroleum. Skimmers are very difficult to adjust for thin films and are highly susceptible to a large water intake when subjected to waves.
Further shortcomings that are known to exist for the removal of petroleum films, such as: with floats and skimmers, transferring to a container using a hose (vacuum), and having a cover with a fan to assist in the gathering of thin films (to make them thicker for easier removal). The skimmer has a pipe with holes along its circumference which blow at the petroleum product, pushing it into the skimmer, as in Soviet patent document no. 402609 (class "YE" 02V15/04).
The problem with such an arrangement is that the air disturbs the water's surface around the skimmer, thereby lowering the surface and reducing the efficiency of the system. To increase efficiency, the skimmer needs to be lowered. With the skimmer lowered, however, greater quantities of water are taken, thereby increasing the water/petroleum product ratio and increasing the amount of water which must later be removed from the fuel. If the state of the water is anything other than dead calm, waves further increase the amount of water picked-up by the skimmer.
With floating skimmers, a vertical tube with holes in it for the removal of the petroleum product is used. This system reduces the amount of water, but it still collects a large amount of water in the water/petroleum product mix. This skimmer also has a cover over the skimmer to reduce water intake due to wave action. Such an arrangement is shown in Soviet patent document no. 1108167 (class "YE" 02V15/04, prototype).
Due to the floats providing minimal neutral buoyancy, the skimmer is subjected to motion due to the volume of fluid in the suction hose and wave action. The skimmer is therefore unable to maintain stability on the surface and only remove the film. Due to wave action, the whole skimmer may be submerged at times. Another shortcoming of this skimmer is the great difficulty in adjusting the skimmer to the film's thickness, which makes initial deployment difficult and time consuming.
This skimmer is effective in removing thick layers of petroleum product, but when the layer is reduced to a film, the skimmer is unable to effectively handle the film. This makes the removal of the film a lengthy drawn out process that is both ineffective and time consuming.